Re: Reading lines of a Text File form the end

From:
Tom Anderson <twic@urchin.earth.li>
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 26 Aug 2010 21:29:41 +0100
Message-ID:
<alpine.DEB.1.10.1008262127010.25456@urchin.earth.li>
On Thu, 26 Aug 2010, Peter Duniho wrote:

Roedy Green wrote:

Your file will be encoded. Encodings are not designed to be
interpreted backwards.


Some are, some aren't (well, I suppose technically none are _designed_ for
backwards use, but many are suitable for backwards use nonetheless). ASCII
works fine in reverse, as does UTF-16, and a number of other pre-Unicode
encodings.


Off the top of my head, i think UTF-8 would be straightforward to read
backwards; there's enough type data in the high bits of each byte to get
the structure right from the wrong end. You'd have to write your own
decoder, but it wouldn't be too hard.

It wouldn't be necessary for this application, though, since that only
needs the lines in reverse order, not a complete backwards stream, and LF
and CR are single-byte characters which can be unambiguously identified in
the stream without having to decode everything in between.

tom

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